METALLURGY OP'IRON AND STEEL.
It is not necessary, that the iron should be brought in a melted state from the blast furnace, as the same procedure can-be:followed when it is charged cold.. Table XII-G shows .the-results from.two series-of heats, in one of. which most of. the metal was charged cold,, while in the other the metal was all, fluid... In these series especial care was taken to have the weights; accurate and to know, the composition and weight of the slag produced. I do not consider that any results on loss, are worth recording unless .the exact amount of pure metallic iron put into the furnace is known and unless this equals the weight of metallic iron in the ingots, the scrap and: the slag. In. addition to this it is well to know, the total amount of, CaO put into the furnace in the form of limestone, burned lime or. dolomite, and see-whether this agrees with the amount of CaO. which is indicated by the. weight and composition of the slag. ID the following two series these conditions were attained and the amount of CaO used was found to check the records of the slag, while the balance sheet of metallic iron agrees within one-fifth 01 one per cent. In individual heats no such accuracy can be obtained,,
TABLE XII-C. Record of -"All-Pig" Basic Open-Hearth Heats at Steelton.
' First Perles. Pounds. Second Series. Pounds.
Liquid metal (1.4 per cent. SI). . . Iron oust in cnil Is .......... v.. 156.200 852 210 405,287
Total metal charged ........... 548,030 410,012
Ore (66.3 per cent. Fe) ....... .... 144,100 116,300,
Ingots ..................... . ..... 551,200 429,000
First slag ......... . ............. . 27,130 73,600
Total slag ............... ....... 44,270 115,100
(Sloa.. 24.04 23.67
Composition of flrat Blag ..... -< CaO. . FeO,. 11.84 41.63 18.14 45.00
(SiO,.. Composition of second slag..-< CaO.. (FeO.. 11.78 ;41.90 26.93 16.14 37.26 . 25.94